wxCFStringRef cfidentifier( identifier, wxFont::GetDefaultEncoding() );
wxNSToolbarItem* item = [[wxNSToolbarItem alloc] initWithItemIdentifier:cfidentifier.AsNSString() ];
[item setImplementation:tool];
wxCFStringRef cfidentifier( identifier, wxFont::GetDefaultEncoding() );
wxNSToolbarItem* item = [[wxNSToolbarItem alloc] initWithItemIdentifier:cfidentifier.AsNSString() ];
[item setImplementation:tool];